In the prior art, self-righting training cups were made by heavily weighting their bases. Despite the very substantial base weight, however, the prior art cups will not right themselves when filled.
It is a principal object of this invention to provide a training cup which is consistently self-righting even when filled. It is a further object of this invention to provide a relationship by which, based on the dimensions of the cup, the proper minimum base weight can be determined and provided.